The concept of using a piezoelectric motor to power heart assist devices or artificial hearts has been suggested in the past. Piezoelectric devices have the advantage of low power requirements, little heat dissipation and little noise as compared with other types of electrical, pneumatic, or mechanical drive systems. Nevertheless, piezoelectric drive systems have not been successful in pumping human blood systems because the output frequency, pressure, and displacement were not compatible with the requirements of a human or artificial heart. Therefore, these previous devices required auxiliary equipment such as valves to produce the desired output thereby adding to the size, additional controls and power requirements, none of which has proved practical.
The present invention is directed to an improved valveless piezoelectric drive system and its use in actuating various types of fluid systems in a human body.